The Present invention relates to material handling platform in general, and more particularly to reduced height load supports.
Shipping and Storage are significant cost components of any product which must make its way from a manufacturer to an end user. The bundling of multiple items into uniform loads with associated structure for engagement by material handling equipment such as forklift trucks has permitted a degree of automation and repeatability in the transportation of goods.
For many years uniform or "palletized" loads were built upon wooden pallets. The wooden pallet is very stiff, is manufactured from commonly available low cost material, and provides a large vertical clearance to receive the metal tines of a forklift truck or the wheeled tines of a hand truck. More recently, plastic pallets have been substituted for wooden ones in view of their greater consistency, usable life, and nestability.
For some loads, however, the high profile of the wooden or plastic pallet, approximately 4-5 inches, represents an unacceptable increase in the shipping volume of the product. This is a particular concern in automated loading applications, such as on railway freight cars, where excessive vertical height of the palletized load of even a few inches might limit the number of stackable units to two levels, rather than three. To minimize support height, loads may be placed on narrow slip sheets, which provide no clearance for fork tines. The conventional slip sheet may be formed of corrugated paperboard, or an extruded or molded plastic sheet, which may have a corrugated paperboard sheet adhesively attached thereto. The slip sheet is typically wider than the load supported thereon, extending outwardly in an upwardly extending lip. In addition to being of lower volume, slip sheets are usually of lower cost than a full height pallet.
Where slip sheet mounted loads are widely used, material handling facilities are outfitted with specialized forklift trucks which have mechanisms for clamping on to the slip sheet lip and dragging the load onto the forklift tines. The slip sheet supported load is usually discharged from the truck by a vertical panel actuated by a scissors joint linkage which pushes the load off the tines.
The conventional slip sheet has several limitations. First, because of its very low-profile, generally from 1/8 in. to 1/4 in., its rigidity is low, and its resistance to warping, twisting, bending, and folding is correspondingly low. This susceptibility to damage in shipping makes re-use problematic. Second, the narrow sheet provides minimal isolation of the supported load from support surface irregularities such as gouges, cracks, loose hardware, splinters and the like commonly found in semi truck trailers, rail cars, and factory floors. The nonrigid slip sheet also provides minimal load distribution of the lifting fork tines. The load is thus open to damage from the concentrated impact of the material handling equipment. Third, facilities which handle primarily loads on high-profile pallets or skids may not be equipped with specialized slip sheet handling equipment. In some situations a slip sheet supported load may be engaged by conventional powered forklift trucks by ramming the tapered tines beneath the slip sheet lip. This approach offers significant opportunity for product damage.
What is needed is a low-profile load support which provides some protection for the load from support surface irregularities and load handling impact, and which is readily engaged by conventional fork lift equipment.